1. Field of the Invention
The present invention relates to an image processing system, an image processing method, an image processing program, and a storage medium that stores the program for executing the image processing method on a computer, and more particularly, to an image processing system, method, program, and storage medium that implements color universal design.
2. Description of the Related Art
Conventionally, as an example of a practical application of color universal design that takes into account the disability of people with color amblyopia, converting color schemes of control panels, operation screens, and important parts of apparatuses into colors that people with color amblyopia can easily recognize exists. As for image outputting apparatuses, just such a method of color conversion has been proposed (e.g., JP-2003-223635-A), as has a method that adds different patterns and textures to each color (e.g., JP-2004-178513-A).
However, while the methods described above can satisfy the fundamental principle of color universal design, i.e., to facilitate image recognition for people with color amblyopia, it is not always true that people with no disabilities can have a sense of satisfaction when they look at printouts applying color universal design.
For example, with the method that converts colors used in an image into colors that people with color amblyopia can easily recognize, while it is effective enough if individual colors can be distinguished or the fact that a highlighted part is colored can be recognized as in the case of text, line drawings, and graphs, the number of colors that can be used to that effect is severely limited and sometimes it is difficult to convert an image that uses many colors.
Also, as for images whose original color scheme is well-known and objects whose proper color scheme is popular, such as specific persons, animals, still lives, natural things, artifacts, characters, trademarks, and designs, sometimes remarkably different and unintended impressions can be produced by the color conversion described above. Since there are various types among people with color amblyopia whose color vision has different characteristics and it is normally assumed that people with no disabilities also utilize the same objects, applying color universal design coloration to image data that have normal coloration can bring users discomfort.
As for the method that adds different patterns and textures to each color, discomfort due to difference in colors is not evoked since the coloration itself does not change. However, the situation is the same as the former color conversion described above, in that the kinds of patterns and textures that can be utilized are not enough compared to number of colors supposed to be used, and in some cases color density is changed depending on the pattern (gradation characteristics are changed.) Generally speaking, human beings are sensitive to irregular gradation (reversion and discontinuity.) In addition, since people with color amblyopia are especially sensitive to change in contrast and color tone compared to people with no disabilities, failure in gradation balance can cause discomfort to people with color amblyopia.
Moreover, since adding texture is a process that intentionally adds noise data that does not exist in the original data, that basically degrades the image quality. Also, sometimes a texture can produce a three-dimensional impression even though it is a two-dimensional pattern, as can be seen with reference to FIGS. 4 (c) and (d). Selection of a texture pattern that does not suit the solidity of the original image can confuse the user.
It is not easy for all creators to share common perceptions to try to create documents by selecting number of colors and coloration carefully keeping true color universal design in mind to avoid the issues described above. Color universal design-conscious coloration drastically limits freedom of presentation, and processing and searching for suitable images takes excessive effort for users who want to make them luxurious intentionally to catch viewers' attention.